Angular using PrismJS - Line Numbers Not Showing

Question

I am developing an app in Angular, which uses PrismJS to display some code sent dynamically, depending on the button selected. The following code displays the line numbers correctly.

<pre class="line-numbers" data-start="5">
 <code class="language-markup">
  &lt;div&gt;&lt;a data-icon="fa-file-o"&gt;File&lt;/a&gt;&lt;/div&gt;
 </code>
</pre>

But using the PrismJS like this will not show line numbers at all.

<pre class="line-numbers" data-start="5">
 <code class="language-markup" [innerHtml]="myCode">
 </code>
</pre>

Would really like to know why exactly this is happening, does the Prism Line Numbers plugin checks the block of line between the code tags? If so is there any way to pass the code dynamically using Angular and specify the starting line number?

Thanks